B6.3.5 Flashcards
Example of a viral plant disease
Tobacco mosaic virus
What are the symptoms of tobacco mosaic virus
It attacks leaves making them mottled or discoloured by preventing chloroplasts from forming, stunting the growth of the plant.
How is tobacco mosaic disease prevented from spreading
Plants should be removed and hands and equipment washed between planting. Crops that are resistant to the virus should be planted on the previously affected area.
Example of a bacterial plant disease
Agrobacterium tumefaciens
What are the symptoms of Agrobacterium tumefaciens
It causes the production of large tumour like growths called galls. As the disease progresses the galls can encircle the plants stem or trunk cutting of the flow of sap. Causing stunted growth or death.
How is Agrobacterium tumefaciens stopped from spreading
Infected plants must be destroyed and removed. Planting other susceptible plants in the area should be avoided for the next 2 years.
Example of a fungal plant disease
Powdery mildew
Symptoms of powdery mildew
Infected plants displays white powdery spots on the leaves and stems.
How are the symptoms of the fungal disease
It reduces growth and makes leaves drop of early.
How is powdery mildew stopped from spreading
It can be controlled by spraying the crop with fungicide.